The subject matter disclosed herein relates generally to fuel systems for internal combustion engines, and, more specifically, to fuel pumping systems for gas turbine engines, such as aircraft engines.
Fuel pumping systems on gas turbine engines may utilize a single positive displacement pump operating in conjunction with a bypassing control in which excess fuel flow is recirculated to the pump inlet. Under some conditions (e.g., cruise), the amount of fuel being pumped may far exceed the amount of fuel required, and a majority of the pumped flow may be recirculated.
The problem: Continual pumping to required pressure followed by recirculation of flow to the pump inlet at low pressure may result in excess fuel pumping horsepower consumption and may reduce efficiency in terms of engine specific fuel consumption (SFC) and heat imparted to the fuel system.